CKD and Kidney Stones: Recognize before it’s too late

Kidneys, bean shaped organs, are located just below the rib cage, one on each side of the spine. Kidneys have significance in body functionality by keeping the composition or makeup of the blood stable. They (a) prevent the buildup of wastes and extra fluid in the body (b) keep levels of electrolytes stable, such as sodium, potassium, and phosphate (c) make hormones that help

• regulate blood pressure
• make red blood cells
• bones stay strong

CKD (Chronic Kidney Diseases) is sometimes called a “silent disease.” Patients rarely feel sick until their kidney disease is advanced. Symptoms may include:

• Fatigue
• Trouble concentrating
• Poor appetite
• Trouble sleeping
• Muscle cramping at night
• Swollen feet and ankles
• Puffiness around eyes, especially in the morning
• Dry, itchy skin
• More often urination, especially at night

Black and south Asian people are three to five times more likely to have kidney failure than white people, but many are unaware of the condition.

Kidney Stones & Chronic Kidney Diseases:

Causes of kidney stones are as follows.

• Calcium
• Ammonia
• Oxalate
• Uric Acid (a waste product produced when the body breaks down food to use as energy)
• Cysteine (an amino acid that helps build protein)

Certain medical conditions can lead to an unusually high level of these substances in urine.

Kidney stones are more likely to develop if the fluid intake is low.

Kidney stones and Chronic Kidney Diseases affect 5% and 13% of the population respectively. Infection stones (struvite) may lead to an obstructive nephropathy with staghorn calculi and are the leading cause of ESRD (End Stage Renal Disease) attributed to nephrolithiasis. Kidney stones could be considered a contributing factor in developing and progression of CKD (Chronic Kidney Diseases). One of the roles of the kidney is to excrete metabolic wastes such as calcium and oxalate at supersaturated concentrations yet prevent precipitation of crystals. Thus, stone formation could be considered an imbalance between the substances which are dissolvers of crystal and promoters by and large. This leads to kidney diseases.

There is evidence that the risk for CKD varies by stone type, but more studies are required. Population based studies often lack the granular detailed data to characterize stone type because many stone formers never have their stones analyzed or urine chemistries evaluated, and, even if so, this information often is not available in the databases available for study. Informal researches indicate that 70% of the stones are Calcium Oxalates.

Kidney Stones & Diet:

Diet plays an important role in the pathogenesis of kidney stones. Because the metabolism of many dietary factors, such as calcium, may change with age, the relation between diet and kidney stones may be different in older adults. Uncertainty remains about the association between many dietary factors, such as vitamin C, magnesium, and animal protein, and the risk of kidney stone formation. Importance of individual dietary factors in the development of symptomatic kidney stones is high. Foods that are high in calcium, potassium, and magnesium should be evaluated as part of a diet to reduce the risk of kidney stone recurrence. Although vitamin C intake is associated with an increased risk of stones, the high amount of potassium in vitamin C–rich foods suggests that limiting the intake of dietary vitamin C in men with calcium oxalate nephrolithiasis is unwarranted.

References:

Rule, A., Krambeck, A. and Lieske, C., 2011. Chronic Kidney Disease in Kidney Stone Formers. Clinical Journal of the American Society of Nephrology, 6, pp. 2069-2075.

Rule, A., Bergstralh, E., Melton, L., Xujian, L., Weaver, A. and Lieske, J., 2009. Kidney Stones and the Risk for Chronic Kidney Disease. Clinical Journal of the American Society of Nephrology, [Online] Available at: <http://cjasn.asnjournals.org/content/4/4/804.full.pdf+html>

NHS, 2015, Black and south Asian kidney health. [Online] Available at: <http://www.nhs.uk/Livewell/Kidneyhealth/Pages/BlackandAsiankidneyhealth.aspx>

Curhan, G., Willett, W., Speizer, F. and Stampfer, M., 1999, Intake of Vitamins B6 and C and the Risk of Kidney Stones in Women. Journal of the American Society of Nephrology, 10, pp. 840-845.

Taylor, E., Stampfer, M. and Churan, G., 2004, Dietary Factors and the Risk of Incident Kidney Stones in Men: New Insights after 14 Years of Follow-up. Journal of the American Society of Nephrology, 15, pp. 3225–3232.

By

Dr. Sameeh J. Khan

(Nephrologist)